Enabling timings in Asus M2A-VM

I'm about to build a PC based on an Asus M2A-VM motherboard (a bit cheap, ino) and I would know if you guys knew any BIOS-update that could enable changing the timings?
AFAIK, the board accepts only 5-5-5-18 RAMs but I need it to be 4-4-4-12.